I hate math...

I hate math.  Seriously.  It gives me pains in my head like no other subject.  And, subjects like Physics use a lot of math.  Yet, lately I've been researching Newton's Laws of Motion and found some excellent lessons regarding taijutsu and effectiveness.

As a complete layman on the subject of Physics, I'm going to attempt to explain my thoughts regarding how these Laws apply to martial arts and what we can learn from them in our own training.

Newton Law of Motion #1 - Law of Balance.  A Stationary object will never move as long as all the forces acting on it are balanced.  The forces acting on an object moving at a constant velocity (steady speed) are also balanced forces.  If a car is traveling at a steady speed, the forces are balanced (even in motion).  If that car starts to accelerate or decelerate, then the forces will no longer be equal and balanced.

Think about our balance.  Our own and our uke's balance.  When we move, we alter our balance.  When we stop moving, we alter our balance.  But, when all our parts move in perfect relationship to the velocity, and that velocity doesn't change, then we have balance.  Think about how this is applied in Sanshin no Kata, and especially in nagare (flow).  In addition, there is a timing element of when to change how our uke is moving or being moved, where they are no longer balanced.  This is applied in our Kihon Happo.  This also plays heavily in my current emphasis of keeping moving, as the balance should be maintained through consistent velocity (no speeding up or slowing down/stopping). There are more lessons here, but I'll let you ponder on that yourself.

Newton's Law of Motion #2 - Force = Mass x Acceleration.  This lets us work out the forces at play on an object by multiplying the mass of the object by the acceleration of the object.

Now, I have a few thoughts on this.  In martial arts, force is important.  But, you hear teachers admonish us not to use force.  There is a difference, however, in 2 things:  how that force is generated and where that force is used.  In our taijutsu, we learn to generate force through our movement, relying less on our own muscles.  However, that is not always the case and we need to train so that we have the muscle power when we need it.  The second factor is even more crucial.  Using force against force goes against the basic maxim of most, if not all, martial arts.  Some situations require it.  But, we train to move so that we are at the correct angles and timing and spacing to apply force where it will have the most effectiveness.  In basic taijutsu, this is often from low postures (kamae) and at off-angles (usually 45-90 degrees).

Newton's Law of Motion #3 - Law of Mass.  Mass is how heavy an object is without gravity.  Or, Mass is how much matter (density) an object has.

Size doesn't always matter.  Size can matter, however, when you look at how Mass affects power.  Since it is a key component in the definition of Force, you have to acknowledge it's place in martial arts.  But, don't confuse size with ability.  No matter how big the opponent is, he will always have weak points, vulnerabilities, and can be defeated.  Remember, Force does not just equate to Mass.  It also has Acceleration.  And, with Acceleration comes balance.  When you apply gravity to Mass and Balance, then you start to see where larger Mass (weight) can be a vulnerability.  On a combat level, one's fitness is also challenged when their own muscles and oxygen absorbtion are not developed to carry their Mass through the exertion of conflict.  Then, there's always the psychological and emotional component...

One important factor in our taijutsu is to relax.  Relaxing not only conserves energy and makes the body supple so it can adapt, but it also affects the weight.  Try picking up someone who is tense, then someone who is relaxed like a limp dishrag.  The latter will feel almost double the weight.  So, you add relaxed muscles to the movement, you increase the Mass x Acceleration factor.  Of course, you need to then develop what muscles to use and when to use them to support the impact of a strike or apply leverage (as well as a properly aligned structure that provides stability without having to compensate through your muscles).  You can't defeat someone by being a limp dishrag...

A quick comment regarding structure - structure has to support balance and applied force.  This means that your structure needs to support your Mass against the effects of gravity through the correct alignment of the bone joints of the body, like a house of cards, so that the muscles can relax into the base or framework.  When you apply Force, that structure has to shift alignment in direct proportion to the effect on balance the motion creates.  In addition, just as your skeletal structure should be aligned to support you from gravity, the same structure should also absorb the impact when you apply that force against a target.  The less your skeletal structure can do this, the more you have to use muscles and connecting tissues.  The more you have to use muscles and connecting tissues, the more you waste energy and your balance is further affected.

When you apply the Law of Balance with the Law of Force, keeping correct balance and structure throughout, you have pretty effective taijutsu.